Quote:
Originally Posted by ianbartie
I have a Cherry proximity sensor already fitted with 2 sensing magnets. Was originally going to be an rpm input for the Cougar but the firmware still does not support it (AU version).
I hooked it up to 12V with a 2.4K pullup resistor & tested the output. Got 12V pulses OK but the tacho does not respond.
The output on the scope showed the square wave from the sensor is about 90% on & 10% off.
The original square wave driving the tacho was 50% on & 50% off. I scoped it before I pulled the motor out.
I can follow circuit diagrams & make something but I don't know how to go from the signal I have got to the signal that I need.
Driving the tacho seems to be a bit of a problem for many EVs.
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Ian,
I am using a cherry proximity sensor as well, with two 5mm diameter rare earth magnets embedded 180 out on an aluminum collar on the back of my motor shaft. They recommend a 2.4K pullup, but I used a 1K since its rated to 25mA. Being rare earth magnets the fields are strong, but my duty cycle is nowhere near 90/10. I'll have a look on the o-scope tonight and let you know what it is.